JPH0764692B2 - Lining method for biofouling prevention body - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for lining a biofouling preventive body having a function of preventing the adhesion of marine organisms such as barnacles, purple shellfish and algae.

[0002]

2. Description of the Related Art Marine structures in contact with seawater are constantly exposed to fouling due to the adhesion of marine life. Therefore, not only the appearance of the ordinary marine structure is impaired but also the functional structure is impaired. For example, in the case of a ship, the resistance increases due to the adhesion of sea life to the bottom surface of the hull and the like, and the propulsion speed of the hull decreases. Further, in the case of a thermal power plant, if marine organisms adhere to the seawater intake pit, the flow of seawater, which is a cooling medium, may be impaired, and power generation may have to be stopped.

For this reason, many techniques for preventing adhesion of marine organisms have been studied in the past. Among them, one of the techniques for preventing adhesion of marine organisms, which is currently in practical use, is a paint containing cuprous oxide or organotin. It is a method of applying to the contact surface of the marine structure with seawater. Further, JP-A-60-209505 discloses a biofouling-preventing pressure-sensitive adhesive body in which a primer layer is provided on one surface of a plate made of copper or a copper alloy, and a pressure-sensitive adhesive layer is formed on the primer layer.

[0004]

However, according to the conventional method for preventing biofouling using a paint, even if the paint is applied thickly, the paint is easily peeled off, so that the life of exhibiting a remarkable antifouling effect is one year. However, it requires complicated maintenance work such as reapplication every year. In addition, JP-A-60-2
Since the marine organism adhesion preventive body disclosed in Japanese Patent Publication No. 09505 uses copper or a copper-nickel (Cu-Ni) alloy, its corrosion resistance and antifouling performance are insufficient.

By the way, as a result of many years of experimental research by the present inventor, when a beryllium copper alloy is used in an offshore structure,
It has been found that it exhibits an extremely excellent effect of preventing biofouling. It is presumed that this is because beryllium ions act synergistically with copper ions to exert a great repellent effect on marine organisms, and prevent adhesion and reproduction of marine organisms. That is, the present inventor has found that the beryllium copper alloy has the effect of exhibiting an antifouling function and the effect of sustaining the elution of copper ions.

An object of the present invention is to provide a lining for a biofouling-preventing body which has good workability for sticking to the inner wall of a pipe, has excellent biofouling-preventing performance and durability, requires no maintenance, and has no toxicity problem. Is to provide a method.

[0007]

In order to solve the above-mentioned problems, a method of lining a biofouling preventive body according to the present invention comprises forming an insulating layer on an inner wall surface of a metal pipe body, and forming an inner wall surface of the insulating layer. The wire mesh made of beryllium-copper alloy is stretched or bonded by a reversal method. The beryllium copper alloy has a beryllium content of 0.2 to 2.8% by weight, and is a Be—Cu alloy, a Be—Co—Cu alloy, or a B—Cu alloy.
It is characterized in that it is any one alloy selected from the group consisting of an e-Co-Si-Cu alloy and a Be-Ni-Cu alloy.

The composition of the beryllium copper alloy is, for example,
Be: 0.2 to 1.0% by weight, Co: 2.4 to 2.7
% By weight, balance Cu and inevitable impurities, Be: 0.2
~ 1.0 wt%, Ni: 1.4-2.2 wt%, balance C
u and unavoidable impurities, Be: 1.0 to 2.0 wt%, Co: 0.2 to 0.6 wt%, balance Cu and unavoidable impurities, Be: 1.6 to 2.8 wt%, Co: 0 ．
4 to 1.0% by weight, Si: 0.2 to 0.35% by weight, balance Cu and inevitable impurities.

The content ratios of cobalt, nickel and silicon selectively contained in the beryllium copper are preferably in the following ranges, respectively. Cobalt (Co): 0.2 to 2.7% by weight Nickel (Ni): 1.4 to 2.2% by weight Silicon (Si): 0.2 to 0.35% by weight Purpose of addition of each element, addition The reasons for limiting the upper limit and the lower limit of the range are as follows.

Beryllium (Be): 0.2 to 2.8 wt% Be is added so that when a biofouling-preventing body is immersed in seawater, Be is eluted to exert a biofouling-preventing effect, and beryllium is added. This is to improve the properties such as strength and corrosion resistance of the copper alloy, to improve the manufacturability such as heat treatment and grain size adjustment, and to improve the formability and castability. If Be is less than 0.2% by weight, the above effects (1) to (7) are not sufficiently exhibited. When Be exceeds 2.8% by weight, the wrought workability deteriorates and the cost becomes economically expensive.

Cobalt (Co): 0.2 to 2.7 wt% Co is added to form fine CoBe compounds and disperse them in the alloy to obtain mechanical properties, heat treatment properties, grain size adjustment, etc. This is for improving the manufacturability of. Co is 0.2
If it is less than wt%, the above-mentioned effects cannot be sufficiently exhibited.
This is because when Co exceeds 2.7% by weight, the flowability of the molten metal deteriorates, the above properties are hardly improved, and the cost becomes economically expensive.

Nickel (Ni): 1.4 to 2.2 wt% Ni is added to form fine NiBe compounds and disperse them in the alloy to obtain mechanical properties, heat treatment properties, grain size adjustment, etc. This is for improving the manufacturability of. Ni is 1.4
If it is less than wt%, the above-mentioned effects cannot be sufficiently exhibited.
This is because when Ni exceeds 2.2% by weight, the flowability of the molten metal deteriorates, the above properties are hardly improved, and the cost becomes economically expensive.

Silicon (Si): 0.2 to 0.35 wt% Si is added to improve the flowability of the beryllium alloy. If Si is less than 0.2% by weight, the effect is not sufficiently exhibited, and if Si is more than 0.35% by weight, the alloy becomes brittle and the toughness deteriorates.

[0014]

According to the lining method of the biofouling preventive body of the present invention,
Since the insulator layer is formed on the inner wall surface of the metal tube body and the wire mesh made of beryllium copper alloy is bonded to the inner wall surface of the insulator layer, the work of bonding the wire mesh made of beryllium copper alloy is relatively simple. Further, the beryllium copper alloy bonded by this method exhibits the repellent effect of marine life in seawater and has the same excellent durability as aluminum bronze and white copper.

[0015]

Embodiments of the present invention will be described below with reference to the drawings. A first embodiment of the present invention is shown in FIG. The first embodiment is an example in which the present invention is applied to a pipe for circulating seawater used in a cooling facility of a power plant.

As shown in FIG. 1, a resin layer 2 made of an electrically insulating material is formed on the inner peripheral wall surface of a cylindrical iron pipe 1 to be buried underground. The electrical insulating material may be glass or concrete, but a resin layer is particularly desirable in terms of workability and economy. Then, the wire net 5 made of beryllium copper is attached to the surface of the resin layer 2. The beryllium copper wire mesh 5 has a cylindrical shape, and is stretched from a pre-folded one on the ground, inserted into the underground iron pipe 1, and stretched on the inner wall surface of the resin layer 2. An adhesive such as thermosetting is applied in advance to the inner wall surface of the resin layer 2 or the outer surface of the wire mesh. Then, the wire mesh 5 is extended in the direction of the arrow shown in FIG. Air, steam, warm water, etc. are introduced into the inside of the wire mesh extended to the inner wall surface of the resin layer 2 to expand the metal mesh and adhere to and adhere to the inner wall surface of the resin layer 2.

As a result of many years of experimental research conducted by the present inventors, beryllium copper alloy has an effect of exhibiting an antifouling function (a function of preventing biofouling) and a continuous effect of elution of copper ions. The effect of exhibiting the antifouling function and the sustained action of elution of copper ions are described in detail below. Effect of antifouling function The ionization tendency of beryllium, copper and nickel is Be> N
It is known from the literature that i> Cu, indicating that the element on the left is more likely to elute. In the case of beryllium copper, beryllium elutes first to form a local battery to exert a biofouling prevention effect due to the current effect, and the beryllium ion takes an oxidized form called internal oxidation. This internal oxidation forms a BeO film inside, for example, as shown in FIG. 3, but since this BeO film is porous, elution of copper is allowed to form Cu ₂ O + BeO on the surface. It is considered that the antifouling function is exhibited by the elution of this copper ion into seawater.

Sustaining action of copper ion elution The above-mentioned effect of exhibiting the antifouling function has a continuing action of eluting copper ions. That is, beryllium copper has an action of continuing the antifouling function without stopping. A dense surface oxide (Cu ₂ O) is formed on the surface of beryllium copper that comes into contact with seawater. However, as shown in FIG. 3, in the lower layer of the surface oxide, internal oxidation of porous BeO is performed. A film of matter is formed. Therefore, the elution of copper into seawater is maintained, and the volume of this film increases due to oxidation. When the volume increase of the film reaches a certain amount, the oxide film on the surface is separated from the porous internal oxide layer. Therefore, it is considered that the electrochemical action and the elution of copper are maintained for a long time.

Further, the continuous action of copper ion elution generated by beryllium copper will be explained as follows using the schematic diagram shown in FIG. 5 when comparing beryllium copper and cupro-nickel. As shown in FIG. 5, when beryllium copper (BeCu) has a certain thickness of a corrosion product (oxide), the corrosion product is peeled off. Then, the surface of the beryllium copper alloy appears, and the thickness of the corrosion product increases as the corrosion progresses again. Then, the corrosion product is peeled off again when it reaches a certain thickness, which is repeated. On the other hand, the elution of ions decreases as the thickness of the corrosion product increases, which gradually decreases. However, when the corrosion products are peeled off as described above, the surface of the alloy appears and the amount of ion elution increases. Therefore, the increase and decrease of copper ion elution are repeated.

The beryllium copper of the embodiment of the present invention has a copper ion elution sustaining action due to the peeling of the oxide film. As a result, the amount of marine organisms adhering to the surface of copper beryllium is small or hardly adhered. On the other hand, as shown in FIG. 4, in the case of cupro-nickel (CuNi) of the comparative example, dense nickel oxide NiO ₂ or copper oxide Cu ₂ O is formed in the surface layer over a certain period of time. This is because the elution of copper ions is suppressed as shown in FIG. This is due to ionization tendency (Be>
According to Ni> Cu), in the case of cupro nickel, nickel (Ni) is considered to preferentially elute to form a local battery, which is due to the formation of a dense oxide on the surface as shown in FIG. Therefore, as shown in FIG. 5, in the case of cupro-nickel, the thickness of the corrosion product initially increases with time, but the growth rate of the corrosion product gradually decreases. At the same time, the elution amount of copper ions gradually decreases. Moreover, with Cupro nickel, flaking of corrosion products does not occur as easily as with copper beryllium. Therefore, the elution amount of ions remains at a low level, and the antifouling effect decreases.

The inventors of the present invention have for the first time discovered that the beryllium copper alloy has such remarkable antifouling effect and copper ion elution sustaining effect. The present inventor is unaware of any prior art document that refers to or points out. As a practical beryllium copper alloy, 11 alloys having a beryllium content of 0.2 to 0.6% by weight and a beryllium content of 1.8 to 2.0% by weight.
Various alloys such as No. 25 alloy are specified by JIS, but those having a beryllium content of 1.6% or more are preferable in terms of antifouling effect. When the content of beryllium exceeds 2.8%, beryllium does not form a solid solution in copper any more, so that the antifouling effect is excellent but the wrought workability is gradually reduced.

Next, a second embodiment of the present invention is shown in FIG. The second embodiment is an example in which the wire net 6 made of beryllium copper alloy is adhered to the inner wall of the tubular body 1 by the inversion method. Water is injected into the pipe body 1 from a water truck. Then, the outer surface of the wire net 6 becomes the inner side by the water pressure, and the wire net 6 is gradually inserted into the tube body 1.

The second embodiment is an example in which the resin layer 2 is formed on the inner wall surface 1a of the pipe 1, dried, and then the wire net 6 made of beryllium copper alloy is attached. It is desirable to use, for example, the inner wall of the tubular body 1 coated with an adhesive for the attachment. According to the second embodiment, there is an effect that the workability of adhering the wire net 6 is good. Further, as in the first embodiment,
The biofouling preventive body with the wire netting 6 lined has good corrosion resistance to seawater and has an effect of exhibiting an antifouling effect.

[0024]

As described above, according to the lining method for a biofouling preventive body of the present invention, a wire mesh of beryllium copper can be attached by a relatively simple operation. Further, according to the biofouling prevention structure to which a beryllium copper wire mesh is attached by this method, it has excellent corrosion resistance, is easy to maintain, has no toxicity problem, and effectively prevents the adhesion of marine life. .

[Brief description of drawings]

FIG. 1 is a schematic explanatory view showing a method of lining an organism adhesion preventing body according to a first embodiment of the present invention.

FIG. 2 is a schematic explanatory view showing a method of lining an organism adhesion preventing body according to a second embodiment of the present invention.

FIG. 3 is a schematic diagram showing a state of an oxide film of beryllium copper according to an example of the present invention.

FIG. 4 is a schematic view showing a state of an oxide film of cupro nickel of a comparative example.

FIG. 5 is a schematic explanatory view comparing changes over time in the amount of copper ions eluted and the thickness of corrosion products for beryllium copper and cupro nickel.

[Explanation of symbols]

 1 Tubular Body (Metal Tubular Body) 2 Resin Layer (Insulating Layer) 5 Wire Mesh (Beryllium Copper Alloy) 6 Wire Mesh (Beryllium Copper Alloy)

─────────────────────────────────────────────────── ─── Continuation of the front page (51) Int.Cl. ⁶ Identification code Internal reference number FI technical display location B32B 15/08 C22C 9/00

Claims (4)

[Claims] 1. An insulating layer is formed on an inner wall surface of a metal tube body,
A lining method for a biofouling preventive body, characterized in that a wire mesh made of beryllium copper alloy is stretched and adhered to the inner wall surface of the insulator layer. 2. The beryllium copper alloy has a beryllium content of 0.2 to 2.8% by weight, and a Be--Cu alloy,
The biofouling-preventing body according to claim 1, which is an alloy selected from the group consisting of a Be-Co-Cu alloy, a Be-Co-Si-Cu alloy, and a Be-Ni-Cu alloy. Lining method. 3. The lining method for a biofouling preventive body according to claim 1, wherein the insulator layer is made of resin, glass or concrete. 4. A lining of a biofouling preventive body, characterized in that an insulator layer is formed on an inner wall surface of a metal body, and a wire net made of a beryllium copper alloy is inverted and adhered to the inner wall surface of the insulator layer. Method.